"Lukasz is happy and Dortmund are a successful club, but Madrid are a worldwide legend," Bartlomiej Bolek told LaSexta.

"We will not make any comment about this, but whoever wants him will have to spend at least €10m."

Meanwhile, AS reports that Bolek has obtained Aitor Karanka's phone number and will contact the Madrid assistant coach to let him know that his client will jump at the chance to move to the Santiago Bernabeu.

Piszczek, who has 22 international caps to his name, has a contract until 2016 with Dortmund, whom he joined from Hertha Berlin in 2010.